Ram upgrade. 4gb->8gb on a new 13" MBP... is it worth it?

I've had my new (mid-2010) 13" MBP for a few months. I'm loving it (first mac, linux convert). I recently got the CS5 Suite and I'm learning After Effects and really really enjoying it.

That said, I feel my MBP is under powered. I got the 2.4 ghz Core Duo w/ 4gb of ram. It was actually gift as I'm starting my masters program.

When I go to render, my computer becomes barely usable (I quit everything I can before I start rendering). So far it's mostly been tutorial project files and template projects that I've rendered, and most use a moderate amount of effects. I'm usually rendering at 720 or 1080 at 30fps. On average it seems to take about 2.5hrs for a 40 second clip w/ H.264 @ 3k/6k.

Would upgrading to 8gb make a significant difference? I'm hoping for faster render times, but also being able to continue using my computer while rendering.

I've found memory from newegg.com for $180 (2x4gb).

This is currently my only computer, so I have plans on purchasing a desktop in the next year that will be more suitable for video production, but for now, would this be a good idea?

Ted is absolutely right. Consider that when using multiprocessing, AE can use 3-4 GB PERCORE. How many cores do you have?

Part of the reason why AE's acting wiggy is because you're trying to use multiprocessing, and you're starving the OS. I'd just turn it off. And unless your laptop's memory capacity gets up near 12 GB, don't turn it back on.